1. Field of the Invention
This invention relates to fire suppression systems and is directed more particularly to a system used in conjunction with a dumb waiter for carrying hazardous materials between floors of a multiple story building.
2. Description of the Prior Art
Sprinkler systems are commonly used to contain or control fire in dumb waiter shafts in multi-story buildings, including in dumb waiters used for carrying hazardous materials, usually chemicals. In such systems, water is used to dilute and wash down spilled materials.
The sprinkler systems in use usually include at least one vapor detector and at least one pull station for each floor. The vapor detectors monitor vapors that have been released into the dumb waiter shaft and automatically activate the suppression system. The pull stations allow for manual activation of the suppression system. The sprinkler systems further include one or more spinkler heads at the top of the shaft, a sump pump for removing water and spilled chemicals from the bottom of the shaft, and a holding tank where water and spilled chemicals pumped from the bottom of the shaft are stored.
When activated, current sprinkler systems release water from the sprinkler head at the top of the shaft. The water flows down the shaft, mixes with spilled chemicals, or the like, and collects at the bottom of the shaft. The sump pump pumps the water and chemicals into the holding tank. Typically, the water is released into the shaft at a rate of 30-40 gallons per minute, and a holding tank of 3,000 gallon capacity is used. Thus, in a little over an hour the tank is nearly filled. If the holding tank reaches capacity, water begins to fill the shaft.
Since the water will have mixed with the chemicals, all of the water must be treated as hazardous waste. It is necessary that the water (with chemical therein) be tested, containerized, and transported to an approved site. Vapors are exhausted to the environment through a roof fan. The dumb waiter system must remain shut down until all water has been removed and the shaft has been decontaminated. If water has seeped from the shaft, those areas of the building affected must also be decontaminated, and must remain closed until the cleanup is complete. It is not unusual for the dumb waiter system to be shut down for two or more days.
There is a need for a fire suppression system which permits faster cleanup and results in a lesser volume of contaminated material for testing, containerizing and shipping to disposal sites.